Evidence of interactions between walleye and yellow perch in New York State lakes

Abstract

We believe that the population dynamics of walleye (Stizostedion vitreum vitreum) and yellow perch (Perca flavescens) are strongly affected by biotic interactions: abundant walleye populations limit perch recruitment, resulting in fast perch and slow walleye growth rates; sparse walleye populations allow for strong perch recruitment resulting in slow yellow perch and fast walleye growth rates. If these mechanisms are important, we would expect a negative correlation between perch and walleye growth rates. Mean length at age 4 for walleye and yellow perch in 23 New York waters were negatively correlated. Further, changes over time in length at age of both species as walleye populations increased in Canadarago and Silver Lakes follow the regression from the whole data set. This indicates a strong interaction between these two percid species in New York waters. The residuals were affected by lake productivity, but not lake area or mean depth. Waters with very low productivity had smaller walleye and yellow perch than expected from the regression.